 /*
  * $Header: /cvshome/build/org.osgi.service.useradmin/src/org/osgi/service/useradmin/Authorization.java,v 1.9 2006/07/11 00:54:01 hargrave Exp $
  *
  * Copyright (c) OSGi Alliance (2001, 2006). All Rights Reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  * http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
 package org.osgi.service.useradmin;

 /**
  * The <code>Authorization</code> interface encapsulates an authorization context
  * on which bundles can base authorization decisions, where appropriate.
  * <p>
  * Bundles associate the privilege to access restricted resources or operations
  * with roles. Before granting access to a restricted resource or operation, a
  * bundle will check if the <code>Authorization</code> object passed to it possess
  * the required role, by calling its <code>hasRole</code> method.
  * <p>
  * Authorization contexts are instantiated by calling the
  * {@link UserAdmin#getAuthorization} method.
  *
  * <p>
  * <i>Trusting Authorization objects </i>
  * <p>
  * There are no restrictions regarding the creation of <code>Authorization</code>
  * objects. Hence, a service must only accept <code>Authorization</code> objects
  * from bundles that has been authorized to use the service using code based (or
  * Java 2) permissions.
  *
  * <p>
  * In some cases it is useful to use <code>ServicePermission</code> to do the code
  * based access control. A service basing user access control on
  * <code>Authorization</code> objects passed to it, will then require that a
  * calling bundle has the <code>ServicePermission</code> to get the service in
  * question. This is the most convenient way. The OSGi environment will do the
  * code based permission check when the calling bundle attempts to get the
  * service from the service registry.
  * <p>
  * Example: A servlet using a service on a user's behalf. The bundle with the
  * servlet must be given the <code>ServicePermission</code> to get the Http
  * Service.
  * <p>
  * However, in some cases the code based permission checks need to be more
  * fine-grained. A service might allow all bundles to get it, but require
  * certain code based permissions for some of its methods.
  * <p>
  * Example: A servlet using a service on a user's behalf, where some service
  * functionality is open to anyone, and some is restricted by code based
  * permissions. When a restricted method is called (e.g., one handing over an
  * <code>Authorization</code> object), the service explicitly checks that the
  * calling bundle has permission to make the call.
  *
  * @version $Revision: 1.9 $
  */
 public interface Authorization {
     /**
      * Gets the name of the {@link User} that this <code>Authorization</code>
      * context was created for.
      *
      * @return The name of the {@link User} object that this
      * <code>Authorization</code> context was created for, or
      * <code>null</code> if no user was specified when this
      * <code>Authorization</code> context was created.
      */
     public String getName();

     /**
      * Checks if the role with the specified name is implied by this
      * <code>Authorization</code> context.
      * <p>
      *
      * Bundles must define globally unique role names that are associated with
      * the privilege of accessing restricted resources or operations. Operators
      * will grant users access to these resources, by creating a {@link Group}
      * object for each role and adding {@link User} objects to it.
      *
      * @param name The name of the role to check for.
      *
      * @return <code>true</code> if this <code>Authorization</code> context implies
      * the specified role, otherwise <code>false</code>.
      */
     public boolean hasRole(String name);

     /**
      * Gets the names of all roles encapsulated by this <code>Authorization</code>
      * context.
      *
      * @return The names of all roles encapsulated by this
      * <code>Authorization</code> context, or <code>null</code> if no roles
      * are in the context. The predefined role <code>user.anyone</code>
      * will not be included in this list.
      */
     public String [] getRoles();
 }

